In communication networks, it is often useful to send the same data to multiple devices at the same time. This is known as a multicast transmission and the devices that are to receive that data are referred to as members of a group or multicast group. Multicasting is useful in both wired and wireless networks.
Wireless networks have the additional restriction that many devices are portable and thus powered by a depleting power supply, e.g., rechargeable batteries. In current wireless networks, there is no means at the physical layer of a frame to address and identify a multicast group. As a result, the multicast frames have to be processed by all devices all the way from physical (PHY) layer/portion of the frame to the media access control (MAC) layer/portion of the frame.